This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. INTRODUCTION: Near-infrared spectroscopy (NIRS) is an increasingly popular technology for studying brain function. NIRS offers several advantages relative to functional magnetic resonance imaging (fMRI), including the ability to measure concentration changes of both oxygenated and deoxygenated hemoglobin, finer temporal resolution, and ease of administration, as well as disadvantages, most prominently inferior spatial resolution, inability to directly measure signals from deep-brain structures, and decreased signal-to-noise ratio (SNR). In this study, we compared NIRS and fMRI signals to assess spatial and temporal similarities. METHODS: Thirteen healthy adults (mean age 27.9, age range 21-42, 6 males) underwent simultaneous NIRS and fMRI scanning while they completed four experimental paradigms: left finger tapping (tap), go/no-go (nog), judgment of line orientation (jlo), and an N-back working memory task using visuospatial stimuli (vis). We performed detailed comparisons of the signals in both temporal and spatial domains. To read about other projects ongoing at the Lucas Center, please visit http://rsl.stanford.edu/ (Lucas Annual Report and ISMRM 2011 Abstracts)